Lack of common sense is the cause. No way would I ever grab hold of a metal object that was plugged into the wall, while I am standing in shoulder deep water.
It's sad for his family.
Maybe, and maybe not.
I'm sure that this was not the first baptism of this sort performed in this church, and I would even go so far as to bet that the electrical system in this church was designed with Ground Fault Interrupters (GFI) to handle this type of use.
So what went wrong with the wiring to cause the GFIs to fail to trip? Has the possibility of homicide been considered? There is more to this story than is in this newspaper article.